A SPACECRAFT that should have given us a spectacular view of the Sun鈥檚 next
peak of activity has been lost. The Solar and Heliospheric Observatory (SOHO)
lost its way last week during a routine manoeuvre.
Since its launch at the end of 1995, SOHO has been sitting at the L1
Lagrangian point, where the gravitational pulls of the Sun and Earth keep it
stable. It carries spectrometers, coronographs and other instruments.
SOHO鈥檚 mission ended in April, but it had enough fuel to keep running until
2002. So mission scientists planned to observe the next peak of the Sun鈥檚
11-year cycle, due in 2000.
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In the early hours of 25 June, SOHO鈥檚 controllers were trying to shed excess
energy from the craft鈥檚 gyroscopes by firing its thrusters. During this
manoeuvre SOHO switched to its Emergency Sun Reacquisition (ESR) mode, in which
it uses a light sensor to right itself. But ground control lost contact. 鈥淲e
don鈥檛 know why the ESR failed,鈥� says Bill Steigerwald, a NASA spokesman at the
Goddard Space Flight Center in Greenbelt, Maryland.
The chances of regaining contact are slim. 鈥淢iracles have happened before,鈥�
says Art Poland, US SOHO project scientist, also at Goddard.